Apparatus for cooling pressed shaped structures



Aug. 1966 B. ROTHER 3,263,441

APPARATUS FOR COOLING PRESSED SHAPED STRUCTURES Filed Nov. 25, 1964 5Sheets-Sheet 1 N P LE B. ROTHER 3,263,441

APPARATUS FOR COOLING PRESSED SHAPED STRUCTURES Aug. 2, 1966 5Sheets-Sheet 2 Filed Nov. 25, 1.964

Aug. 2, 1966 B. ROTHER 3,263,441

APPARATUS FOR COOLING PRESSED SHAPED STRUCTURES Filed Nov. 25, L964 5Sheets-Sheet 5 Fig.5

United States Patent 4 Claims. (a. 62341) This invention relates to thecooling of pressed shaped bodies or structures, such as chipboard, orplates formed of flat shavings, bagasse, etc., by means of a flowingcoolant and, if required, under pressure.

The cooling of the shaped bodies leaving the heating press, having beenpressed into shape at temperatures in the range of about 120185 C., isof particular importance because the sharp temperature drop accompanyingit may easily lead to deformations of the shaped bodies. This danger isespecially great with shaped bodies having the form of plates and thelike, in particular when these have a low thickness. The percentage ofrejects is corresponding high.

On the other hand, the known cooling methods involve, with regard to thespace and time required, a very expensive intermediate storage of theshaped bodies between the press and the finishing steps, in order toensure the necessarily complete hardening required by the subsequentpolishing step.

In a prior proposed cooling process, the shaped bodies are clamped, justas during the preceding heating process, so that they cannot warp or bedistorted during cooling. However, the sudden contact of the shapedbodies, which are still hot, with the cold cooling surfaces of thecooling press causes intensive condensation in the interior of theplate. This premature condensation, resulting from the sharp temperaturedrop, is very detrimental to the properties of the shaped bodiesconcerned, because the water vapour which serves as a carrier of thealmost universally employed synthetic resin binders, plays a decisiverole in the production of said shaped bodies.

Since the cooling press must operate at the same speed as the heatingpress preceding it, slow cooling is not possible in view of the shortheating periods usual in this process.

Moreover, cooling presses of this kind are extremely expensive topurchase and to operate and require a considerable space.

The drawbacks resulting from the above expense are avoided or reduced inanother prior proposed process in which the shaped bodies leaving thepress are swept by a coolant fluid in a cooling canal. To achieve acorrect cooling effect however, the shaped bodies have to be repeatedlydisplaced in this process, e.g. by rotation, being held by clampelements. For this reason, the equipment is rather subject to breakdown;in addition, no safety is offered against warping.

The considerable disadvantages of the known arrangements make itdesirable to seek new ways of cooling pressed shaped bodies, moreespecially chipboard or the like, which satisfy the requirements ofintegrating the cooling process into a largely automatic operation inthe production of such shaped bodies. In particular, it is necessary toeffect the cooling at a rate correspond ing to the output of the pressand to conduct it according to a programme until the shaped bodies reacha state in which their finishing can be under-taken without any furtherintermediate working, storage or the like.

According to the invention there is provided a process for coolingpressed shaped bodies, e.g. chipboard plates, by means of a flowingcoolant and if required under pressure, in which the shaped bodiesleaving the press are transported in steps and are cooled in stepsduring the rest periods of their transport.

The process according to the invention takes into particular account thenature of the materials being processed in an especially advantageousand rational manner in that, by the stepwise cooling, a completehardening of the shaped bodies or of their binders is achieved whileavoiding detrimental condensation or like phenomena and without thedanger of warping. The exploitation of the existing transport path frompress to finishing, i.e. in general to squaring and/or polishing, makesit possible to reduce the temperature of the shaped bodies in a simplemanner and Without additional space requirements.

The invention further provides an apparatus for carrying out the processdefined above, comprising several successive pairs of coolant-irrigatedcooling faces movable in relation to each other said faces beingarranged to receive pressed shaped bodies from the heating press andbeing associated with conveyor means serving for the transport of theshaped bodies.

The arrangement according to the invention renders possible the stepwisecooling of the shaped bodies with the simplest possible means at a ratecorresponding with the press output, to the value corresponding to thedesired physical properties of the shaped bodies. It is further withinthe scope of the invention to choose the number of cooling-face'pairsaccording to practical requirements and to increase or reduce theirnumber optionally.

The invention is not limited to a specific spatial position of thecooling faces. The latter may be arranged in a horizontal plane as wellas in vertical or any other position, so that a maximum adaptability toexisting conditions results.

If the arrangement is employed in conjunction with an installation forreturning the sheet-metal forms or moulds from press to strewingmachine, then the invention further provides for the cooling-face pairsto be arranged under or above the conveyor returning the sheet-metalforms. This arrangement avoids any additional spatial requirements andmay utilise the structural elements of the conveyor for sheet-metalforms.

According to another feature of the invention, the cooling facescomprise coiled pipes with a flat face facing the shaped bodies, onecooling face of each pair being vertically displaceable in relation tothe other. This arrangement makes possible a direct heat transferbetween the cooling faces and the surfaces of the shaped bodies to becooled, while allowing an unhindered movement of the shaped bodies alongthe cooling path, i.e. from the coils of one cooling-face pair toanother.

The arrangement according to the invention is preferably operatedcounter to the flow of the coolant which is accordinglyfed in at thetake-off end of the cooling path and led out at the first pair ofcooling faces at the input end of the cooling path. The coolant isexpediently re-circulate-d through a heat exchanger and a pump. Theinvention provides for the possibility of series-connecting theindividual cooling coils of the faces and the pairs of faces in thedirection of the flow. Accordingly, the coolant will flow through bothpipe coils of a pair before entering the next pair.

On the other hand, it is also possible to series-connect separately thecooling face coils on either side of the pairs. In this arrangement, thecoolant circuit is expediently divided at one end of the cooling pathand is united again at the other end.

According to a further feature of the invention, the pipe coils of thecooling faces extend in the direction of the transport of the shapedbodies. However, under certain circumstances it may be expedient to havethe pipes extending transversely to the direction of advance of theshaped bodies.

Mobility of the individual cooling faces of a pair is provided accordingto the invention by movably connecting the adjacent pipe coils of thecooling faces to each other. This movable connection is provided bothbetween the two pipe coils of a given cooling-face pair and betweenadjoining pairs. Expediently, flexible pipe joints are used for thispurpose.

It is further within the scope of the invention to arrange the pipecoils of successive cooling face pairs staggered in relation to eachother in such a manner that a pipe interval is succeeded by a pipe onthe next following pair of faces, and vice versa. This arrangementensures that the surfaces of the shaped bodies are exposed substantiallyuniformly to the coolant during their passage along the cooling path.

As further provided according to the invention, conveyor elements arearranged on one side at least of the cooling-face pairs. In a horizontalarrangement of the individual cooling faces this corresponds to thelower cooling faces on which the shaped bodies rest.

In order to avoid hindering the cooling process, the conveyor elementsare arranged, according to another feature of the invention, so as to bemovable from an engaged position into a rest position in relation to theshaped bodies. This is to be understood as a movable mounting of theconveyor elements and also as a fixed mounting of the latter with asimultaneously movable arrangement of the cooling surfaces positioned atleast on the side of the conveyor elements.

In further development of the invention, each of the cooling-face pairsis provided with at least one powered axle, extending transversely tothe direction of transport, on which axles discs or similar elements aremounted so as to project into the intervals between the coolant pipecoils with their peripheries projecting beyond the plane of the coolingfaces in the engaged position. When the two cooling faces of a pair aremoved away from each other, the conveyor elements come into engagementwith the shaped bodies and move these in the intended direction oftransport into the next following coolingface pair.

In a particularly advantageous arrangement, the conveying axles of eachcooling face pair have a common drive. The drive may be continuous orintermittent. It is also quite possible to give a common drive to allconveyor elements.

According to a further feature of the invention, the two cooling facesof a pair are each hingedly connected at opposite ends to two lateralpivot levers which are fixedly and substantially centrally mounted andone of which is engaged by a setting mechanism.

This results in a particularly advantageous mounting of the coolingfaces of each pair, having regard to weight compensation. However, thisarrangement also renders possible a fixed mounting of the conveyorelements which, when the two cooling faces move away from each other,project above the cooling faces and come into engagement with thecontact surface of the shaped bodies.

Further features, details and advantages of the invention will beapparent from the following description of a preferred embodiment withreference to the accompanying drawing wherein:

FIG. 1 is a schematical plan view of an installation for producingchipboard panels or like pressed shaped bodies;

FIG. 2 is a view along the line II-II of FIG. 1;

FIG. 3 is a fragmentary plan view on an enlarged scale;

FIG. 4 is a side elevation of a section of the cooling path according toFIGS. 1 and 2, on a further enlarged scale; and,

FIG. 5 is an enlarged section on the line VV of FIG. 3.

Referring to FIGS. 1 and 2 of the drawings, the installation as a wholeincludes a strewing machine, indicated at 1, in the region of which thesheet-metal forms required for shaping are covered with a chip matprovided with the binder and possibly other additives. The filledshaping irons pass along conveyor 2 into a heating press designated bythe reference 3, from where they are ejected in the direction of arrow4. In the region of position 5, the pressed shaped bodies (chipboardpanels in this embodiment) are removed from the sheet-metal forms herenot shown in detail, by a takeoff device 6, which may for exampleconsist of a suction plate; the sheet metal form in turn moves overconveyor 7, in the direction of arrow 8, on conveyor 9 and is moved backby means of the latter and the adjacent intermediate conveyor to thestrewing machine. The only schematically indicated shaping-iron return 9is located below cooling path designated by 11.

Shaped bodies 12 gripped individually by the transverse conveyor 6 andcarried between guide rails 13 are passed to input 14 of the coolingpath 11. The latter is defined by cooling faces 15 arranged in pairs oneabove the other; the faces 15 are formed by coolant pipe coils 16, whichextend along the cooling path 11 in the direction of advance of theshaped bodies as indicated by arrow 17. At the takeoff end 18 of thecooling path 11, the coolant enters at 19 into the upper or lower pipecoil 16 of cooling-face pair 15' and, after flowing through both pipecoils 16 of this pair 15' which are connected to each other by aflexible pipe joint, passes through a further flexible connection 20into the coils of adjacent cooling-face pair 15". The coolant progressesin this manner until it reaches the coils of cooling-face pair 15adjacent the input 14 of the cooling path, from which it emerges at 21,and is fed to a heatexchanger 22 with a series-connected pump 23. Thecooled and hardened boards then leave the cooling path at output 54 andpass to the finishing line.

FIGS. 3 and 4 illustrate a section of the path 11, namely a top view ofa pair of cooling-faces 15 in the form of the pipe coils 16, the lowerof which is virtually hidden by the upper one. Each pipe coil 16 isfastened to two transverse shafts 25 of which the lateral ends aremounted in rocking levers 26. Pipes 27 of the coils 16 have arectangular cross-section and intervals 28 between these pipes arenarrower than the width of the pipes. As FIG. 5 shows, bearing pin 29 ofeach upper shaft 25 and lower shafts 25', is attached by means of asupport 30. The rocking lever 26 is mounted, on axis 38 (FIG. 3) onlateral support 31, which rests on support 32.

A flexible pipe joint between the two pipe coils 16 of the cooling-facepair 15, indicated in FIGS. 3 and 4, is shown at 33. A further flexiblejoint 34 constitutes the connection between each pipe coil and that ofthe next following cooling face.

On one of the lateral supports 31 of the cooling path 11 there ismounted a setting motor 35, an axially extensible setting member 36 ofwhich engages at 37 the rocking lever 26'. On extending the settingmember 36, all four rocking levers required for disengaging a pair ofcooling faces 15 are pivoted, about their axes 38, so that faces 40 ofthe pipes 27 facing board 39 move away from each other, in that theupper cooling face moves upwards and the lower cooling face movesdownwards from the closing position.

On transverse supports 42, connected to the longitudinal supports 31,there are mounted bearings 43 which carry shafts 44; in the presentexample seven shafts are provided for each cooling-face pair. Discs 45which enter the pipe intervals 28 of the coils 16 are secured to theshafts 44. In the position shown in FIG. 5, where the two pipe coils 16of a cooling-face pair 15 are moved away from each other so that spacing46 is greater than the thickness of the board 39, the discs 45 projectabove the surface 40 of the lower coil 16 by an amount of x. Hence, theboard 39 is lifted from the corresponding supporting surface 40 andrests solely on the discs 45. The discs 45 are set in rotary motion bymeans of motor 47 as well as by means of beltor chain-transmission 49,48 in the direction of arrow 50, so that the boards are moved in thedirection of arrow 51 (FIG. 4) and are passed on to the next followingcooling-face pair.

As FIG. 3 shows, the pipe intervals 28 or 28 of two successivecooling-face pairs 15 are so arranged that they are not aligned.

The invention is of course not limited to the form of embodimentdescribed in the foregoing and illustrated in the drawing; rather,numerous modifications thereof are possible without deviating from thefundamental concept of the invention. Thus, for example, theinstallation according to the invention is by no means restricted to theproduction of chipboard panels, plates or like bodies; the latter merelyrepresents a preferred field of application.

I claim:

1. Apparatus for cooling to room temperatures hot pressed articles toavoid cooling stresses and distortion therein comprising:

a plurality of pairs of superposed heat exchange members arranged insubstantial alignment to define an elongated cooling path;

means for moving the heat exchange members of each pair toward and awayfrom each other;

conveyor means extending through one heat exchange member of each pairto convey the articles from one pair to the pair next adjacent thereto,said conveyor means comprising a plurality of rotatably-driven diskswhich engage with the undersurface of the articles to urge them alongsaid elongated cooling path;

and means for circulating a fluid coolant through all of said heatexchange members.

2. Apparatus as defined by claim 1 in which said heat exchange memberseach comprise a plurality of flat hollow conduits arranged in aserpentine configuration with the spacing between adjacent convolutionslying substantially parallel to each other and in the path of travel ofthe articles therealong.

3. Apparatus for cooling to room temperatures hot pressed articles toavoid cooling stresses and distortion therein comprising:

a plurality of pairs of superposed heat exchange members each comprisinga plurality of fiat hollow conduits arranged in a serpentimeconfiguration with the spacing between adjacent convolutions lyingsubstantially parallel to each other and to the path of travel ofarticles therealong, so that pairs of heat exchange members beingfurther arranged in substantial alignment with each to define anelongated cooling path;

a plurality of shafts extending transversely beneath said heat exchangemembers;

a plurality of discs rigidly attached to said shafts, said discsextending into the spacing between adjacent convolutions of said heatexchange members;

means for positively driving said shafts to rotate said discs;

means for displacing the heat exchange members of each pair in avertical plane toward and away from each other whereby said discsperiodically extend completely through the lower heat exchange member ofeach pair to engage the articles thereon and convey them to the nextadjacent pair;

and means for establishing a positive circulation of fluid coolantthrough all of said heat exchange members.

4. Apparatus as defined by claim 3 in which said heat exchange membersare connected in a closed series coolant path and in which the coolantis circulated through said members in a direction which is counter tothe flow of the articles therealong.

References Cited by the Examiner UNITED STATES PATENTS 2,687,920 12/1954Mackenzie 62-341 2,927,443 3/1960 Knowles 62341 2,993,345 7/1961Franklin 6263 ROBERT A. OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner.

1. APPARATUS FOR COOLING TO ROOM TEMPERATURES HOT PRESSED ARTICLES TOAVOID COOLING STRESSES AND DISTORTION THEREIN COMPRISING: A PLURALITY OFPAIRS OF SUPERPOSED HEAT EXCHANGE MEMBERS ARRANGED IN SUBSTANTIALALIGNMENT TO DEFINE AN ELONGATED COOLING PATH; MEANS FOR MOVING THE HEATEXCHANGE MEMBERS OF EACH PAIR TOWARD AND AWAY FROM EACH OTHER; CONVEYORMEANS EXTENDING THROUGH ONE HEAT EXCHANGE MEMBER OF EACH PAIR TO CONVEYTHE ARTICLES FROM ONE PAIR TO THE PAIR NEXT ADJACENT THERETO, SAIDCONVEYOR MEANS COMPRISING A PLURALITY OF ROTATABLY-DRIVEN DISKS WHICHENGAGE WITH THE UNDERSURFACE OF THE ARTICLES TO URGE THEM ALONG SAIDELONGATED COOLING PATH; AND MEANS FOR CIRCULATING A FLUID COOLANTTHROUGH ALL OF SAID HEAT EXCHANGE MEMBERS.